A281587 - OEIS

%I #5 Feb 01 2017 13:44:41

%S 1,1,1,1,2,1,1,3,3,1,-1,4,6,4,1,-4,-5,10,10,5,1,-14,-24,-15,20,15,6,1,

%T -34,-98,-84,-35,35,21,7,1,69,-272,-392,-224,-70,56,28,8,1,496,621,

%U -1224,-1176,-504,-126,84,36,9,1,2896,4960,3105,-4080,-2940,-1008,-210,120,45,10,1

%N Triangle read by rows, e.g.f. exp(x*z)*(2*(exp(z)+1)/(cosh(z)+cos(z))-1).

%e Triangle starts:

%e [   1]

%e [   1,   1]

%e [   1,   2,   1]

%e [   1,   3,   3,   1]

%e [  -1,   4,   6,   4,  1]

%e [  -4,  -5,  10,  10,  5,  1]

%e [ -14, -24, -15,  20, 15,  6, 1]

%e [ -34, -98, -84, -35, 35, 21, 7, 1]

%p A281587_row := proc(n) exp(x*z)*(2*(exp(z)+1)/(cosh(z)+cos(z))-1);

%p n!*coeff(series(%,z,n+1),z,n); PolynomialTools:-CoefficientList(%,x) end:

%p for n from 0 to 12 do A281587_row(n) od;

%Y Cf. A130595 (m=1), A109449 (m=2), A215064 (m=3), A281587 (m=4).

%Y Cf. A178964 (col. 0), A281588 (col. 1).

%K sign,tabl

%O 0,5

%A _Peter Luschny_, Feb 01 2017